1. Field of Invention
The present invention relates generally to a device to assist in pulling electrical wire through underground conduit.
More particularly, the invention relates to an electrical underground wire pulley which, while suitable and adaptable for other uses, is specially adapted to assist in pulling electrical wire through underground conduit between concrete base structures of the type used with light poles and some outdoor electric signs. 
2. Description of Prior Art
A typical parking lot light, street light, and some electric signs, include a concrete base that is set into the ground, and a pole secured to the base with four nuts threaded onto threaded studs, commonly referred to as anchor bolts, that are anchored into the base. Electrical wire is run to the base through underground conduit, the pole is secured to the base, and electrical connections are made through an access panel in the side of the pole.
The conventional technique to pull electrical wire through underground conduit is to first thread a thin rope or starter cable through the conduit, connect one end of the starter cable to the electrical wire, and then pull the starter cable and electrical wire back through the conduit until sufficient length of the wire extends out the end of the conduit to make the electrical connections in the pole.
In many instances, such as commonly encountered between parking lot lights, the electrical wire is pulled manually through the conduit. However, manually pulling electrical wire through the underground conduit can be difficult due to friction between the conduit and the wire, particularly as the length of the conduit increases, as the clearance between the wire and the conduit decreases, and if the wire is supplied or pulled at a significant angle that is not perpendicular to the conduit opening, all of which increase the friction between the  wire and the conduit. Due the high pulling forces that may be required, this manual technique also presents the possibility of accidents and injury to the persons pulling the wire. The conventional configuration of parking lot lights further complicates pulling wire through the conduit. The concrete base of a parking lot light is typically extends to a height of 2 to 3 feet above ground. This height adds to the difficulties and dangers of manually supplying wire into and pulling wire through the conduit. If standing on the ground, the installer can achieve only limited leverage with which to pull the wire, and standing on the top of the base, for additional leverage, creates obvious hazardous conditions. Such manual operations also present the potential for damage to the wire due to sharp bends that may accidentally develop in the wire while supplying the wire into the conduit.
Specially adapted trucks or other relatively large, specialty equipment is sometimes used to pull cable through underground conduit, particularly through long lengths of conduit as may encountered between street lights. However, the relatively high cost associated with the purchase, maintenance and use of such equipment typically precludes its economical use in many instances and to smaller contractors. Certain prior portable, less expensive pulley devices are known in the art to assist in pulling wire through conduit. However, none of these known devices are particularly suitable to assist in pulling  wire through conduit between concrete base structures of the subject type. Consequently, pulleys designed for different purposes are sometimes used in make-shift arrangements, such as suspending a pulley on a chain from the boom of a bucket truck, or otherwise rigging a pulley above the conduit, to enable manually supplying the wire and pulling the wire either manually or with a motor vehicle. Such arrangements can be difficult and time consuming to setup and use, and they remove the equipment from the use for which it was intended. Further, if not setup and used carefully, such make-shift arrangements can also create unsafe working conditions and the possibility of injury.
Consequently, there is a need for an improved device to address the above-noted drawbacks and disadvantages of the prior methods and apparatus to pull wire through underground conduit. In particular, there is a need for a new and improved device that is specially adapted to assist in pulling wire through underground conduit to or between base structures of the subject type, and that is, among other things, cost effective in fabrication and use, easy to setup and use, easy to transport from one base structure to another, and promotes user safety by eliminating the dangers associated with manual unassisted pulling of wire through underground conduit and previously used make-shift pulley arrangements. 